Interaction of the anticancer drug epirubicin with DNA

The interaction of epirubicin (EPR) with calf thymus double-stranded DNA (dsDNA) and calf thymus single-stranded DNA (ssDNA) was studied electrochemically by using differential pulse voltammetry (DPV) and cyclic voltammetry (CV) at carbon paste electrode (CPE). Experimental parameters, such as the concentration of EPR in CV, the concentration of DNA and the accumulation time of EPR, were studied by using DPV; in addition, the detection limit and the reproducibility were determined. It was observed that the signal at a bare electrode was higher than that at the dsDNA-modified CPE. The signals for EPR in CV were found to decrease in the order of bare CPE, ssDNA-modified and dsDNA-modified CPE. The interaction of EPR with smaller oligonucleotides was also evaluated for use as a hybridization indicator.